In a machine for folding a continuous web assembly in a zig-zag manner, such as disclosed in Loase U.S. Pat. No. 3,250,528 which issued to the assignee of the present invention, the web assembly is directed downwardly between a pair of parallel adjacent rotary cylinders each of which carries a pair of diametrically opposed movable creasing jaws arranged at 90.degree. to a pair of diametrically opposed movable tucker blades. The movable jaws and tucker blades on the cylinders cooperate in an alternating manner to crease and fold the continuous web assembly in a zig-zag manner. Commonly, each fold of the web assembly defines a multiple copy business form assembly, and longitudinally spaced lines of cross perforations are provided within the web assembly to facilitate separating of the business forms after they are processed through a business machine.
It has been found desirable for a zig-zag folding machine to incorporate folding cylinders rather than a pair of folding mechanisms as disclosed in Loase U.S. Pat. No. 2,819,068. That is, the cylinder-type construction has been found more economical both in materials and assembly and also assures that the web folds outwardly away from the outer surfaces of the cylinders instead of inwardly into the rotating folding mechanisms.
It has also been found that when a cylinder folding machine is operated at a relatively high speed for rapidly folding a web assembly, as for example, at a speed of approximately 1000 feet per minute, there is a tendency for each fold of the web assembly to cling to or adhere to the outer cylindrical surface of the adjacent cylinder. This attraction is caused primarily by static electric charges created between the folding cylinders and the web assembly and frequently results in the folds being curled or rolled as they are being stripped or released from the cylinders by adjacent stripping members or pins. As a result of the rolling or curling of the web folds, the overlapping webs are prevented from flowing smoothly and uniformly from the folding cylinders, and occasionally the curled folds will collect and jam the machine.